Abbreviation for Transmission Control Protocol/Internet Protocol (TCP/IP) is a commonly used phrase to refer to the entire Internet protocol suite. It is by far the most widely used suite of networking protocols, providing the technical foundation for the public Internet as well as for large numbers of private networks (called internets with a small “i” to distinguish them from the public Internet) that are not linked to the public Internet.
The most important achievement of TCP/IP is its flexibility for lower-level protocols, which—in contrast to the design philosophy expressed in the OSI Reference Model—are not defined. As a result, can work with a wide variety of physical media, including local area networks (LANs) such as Ethernets, frame relay, digital T1 and T3 backbones, fiber optic, packet radio, and many more. See connectionless protocol, connection-oriented protocol, Ethernet, internet, Internet, Internet Protocol (IP), OSI Reference Model, TCP.